Depending on how your video was encoded, you may also have to check that the moov_atom was moved to the beginning of the file. I think Quicktime puts it at the end by default. I think ffmpeg for mac/linux both come with a utility for doing this.

Depending on how your video was encoded, you may also have to check that the moov_atom was moved to the beginning of the file. I think Quicktime puts it at the end by default. I think ffmpeg for mac/linux both come with a utility for doing this.